Journal article
What is the effect of area size when using local area practice style as an instrument?
Journal of clinical epidemiology, Vol.66(8), pp.S69-S83
08/2013
DOI: 10.1016/j.jclinepi.2013.04.008
PMCID: PMC3718893
PMID: 23849157
Abstract
Discuss the tradeoffs inherent in choosing a local area size when using a measure of local area practice style as an instrument in instrumental variable estimation when assessing treatment effectiveness.
Assess the effectiveness of angiotensin converting-enzyme inhibitors and angiotensin receptor blockers on survival after acute myocardial infarction for Medicare beneficiaries using practice style instruments based on different-sized local areas around patients. We contrasted treatment effect estimates using different local area sizes in terms of the strength of the relationship between local area practice styles and individual patient treatment choices; and indirect assessments of the assumption violations.
Using smaller local areas to measure practice styles exploits more treatment variation and results in smaller standard errors. However, if treatment effects are heterogeneous, the use of smaller local areas may increase the risk that local practice style measures are dominated by differences in average treatment effectiveness across areas and bias results toward greater effectiveness.
Local area practice style measures can be useful instruments in instrumental variable analysis, but the use of smaller local area sizes to generate greater treatment variation may result in treatment effect estimates that are biased toward higher effectiveness. Assessment of whether ecological bias can be mitigated by changing local area size requires the use of outside data sources.
Details
- Title: Subtitle
- What is the effect of area size when using local area practice style as an instrument?
- Creators
- John M Brooks - University of Iowa, College of Pharmacy and College of Public Health, S-515 Pharmacy Bldg., 115 S. Grand Ave, Iowa City, IA 52242, USAYuexin Tang - University of Iowa, College of Pharmacy, Iowa City, IA, USACole G Chapman - University of Iowa, College of Pharmacy, Iowa City, IA, USAElizabeth A Cook - University of Iowa, College of Pharmacy, Iowa City, IA, USAElizabeth A Chrischilles - University of Iowa, College of Public Health, Iowa City, IA, USA
- Resource Type
- Journal article
- Publication Details
- Journal of clinical epidemiology, Vol.66(8), pp.S69-S83
- Publisher
- Elsevier Inc
- DOI
- 10.1016/j.jclinepi.2013.04.008
- PMID
- 23849157
- PMCID
- PMC3718893
- ISSN
- 0895-4356
- eISSN
- 1878-5921
- Language
- English
- Date published
- 08/2013
- Academic Unit
- Pharmacy; Epidemiology; Pharmacy Practice and Science
- Record Identifier
- 9983995015602771
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